Recruitment of subjects for this project began in April, 1999. At this time, a total of 22 subjects (11 COPD patients and 11 first-degree relatives) have been recruited and tested. No adverse events have occurred. A computerized methodology for quantitation of emphysema from CT scans has been developed and has demonstrated adequate DNA extraction from our blood samples. Genotyping has been deferred pending the recruitment of 50 subjects.